The oldest magnetic field on Earth discovered – Careers Ready


ancient rocks, which The oldest remains of Earth's early magnetic field have been found, by geologists from MIT and Oxford University greenland Has been discovered in.

related facts

  • This remarkable discovery 'The Journal of Geophysical Research' Published in.
  • Sample for study: for this study 'Isua Supracrustal Belt' located in southwestern Greenland Rock formations were sampled.
    • The composition of the rock sample was similar to that of 'iron'. It is a type of rock in which iron and silica The presence of is visible in the form of stripes.
  • Objective: Finding rocks whose formation was facilitated by the Earth's magnetic field.
  • Process: Through the process of remagnetisation the researchers used varying proportions of uranium and lead, resulting in some magnetic minerals that were approximately 3.7 billion years Were old.

result of investigation

  • rocks approx 3.7 billion years are considered old, in which Capacity of at least 15 microtesla Signs of magnetic field are present.
    • At present the Earth's magnetic field is approximately 30 microtesla Can measure.
  • Origin of Rock: Based on the composition of these rocks, they were probably originally formed around Increase in atmospheric oxygen 2.5 billion years ago Occurred in the oceans before.


  • The discovery extends the lifetime of the magnetic field to 200 million years, the rocks that represent the magnetic field around Earth.
    • Previous studies have found that Earth's magnetic field lasts at least 3.5 billion years It is old.
  • Early evidence on Earth's habitable atmosphere: This discovery sheds light on how the possibilities for life on Earth were being created during Earth's early evolution. The magnetic field was partly responsible for the possibility of life on Earth and was able to protect the planet from harmful solar radiation.

Earth's Magnetic Field

  • This geomagnetic field Is also called. It originates in the planet's interior and spreads into space, creating a region called 'Magnetosphere is referred to as.
  • First search: British polar explorers James Clark Ross For the first time in the year 1831 in the Nunavut region of Canada Magnetic North Pole on the Boothias Peninsula Was identified.
  • place: Magnetic poles are formed at the places where the lines of attraction of the magnetic field enter the Earth. to the magnetic north pole north dip pole (North Dip Pole) Also known as and currently it 'Ellesmere Island' in northern Canada (Ellesmere Island).
    • The magnetic north pole is approximately 310 miles (500 kilometers) away situated at.
  • features
    • Dipolar: The sources of the magnetic field are dipole (north and south poles). In a magnet, opposite poles (North and South) attract each other while other poles (N and N, S and S) repel each other.
      • Therefore, the North Magnetic Pole, which is located close to the geographic North Pole, is essentially south magnetic pole Is.
    • Unstable: The Earth's magnetic poles are not stable and their positions change with time. According to the Royal Museum Greenwich, 'Magnetic North Pole' approximately in the north-west direction 25 miles (40 kilometers) per year Roaming.
    • Magnetic Reversals: Earth's magnetic poles have also turned opposite due to which North and South have changed. this event Regular intervals But it happens.
      • Earth's most recent magnetic reversal is approximately 790,000 years Had happened before.
    • Auroras: It was seen over the Earth's polar regions magnetosphere barrier (Magnetosphere Disturbances) has a characteristic.
      • Disturbances in the Earth's magnetic field pull the ions toward the Earth's poles where they collide with oxygen and nitrogen atoms in the Earth's atmosphere, producing bright light.
      • This event occurred in the Northern Hemisphere Northern Lights or Aurora Borealis (Northern Lights /Aurora Borealis) and in the Southern Hemisphere Southern lights or Aurora Australia Known as (Southern Lights/Aurora Australis).

cause of earth's magnetic field

  • geodynamo process Magnetic field is generated through a medium called (Geodynamo Process). It has the following characteristics-
    • of the planet rotational speed Should be fast.
    • in the interior of the planet liquid medium Must be present.
    • in internal fluid ability to conduct electricity There should be.
    • There must be an internal source of energy in the Earth's core, which convection currents in liquid interior Inspires.
  • Process
    • Earth's magnetic field outer core of the inner part Originates in the layer known as.
    • Conversion of Energy: of molten iron here Electric and magnetic energy to sustainable energy is converted into.
    • Feedback Loop: The magnetic field induces electric currents, which are capable of generating their own magnetic field.
  • Importance
    • Protected Atmospheric Layer: The magnetosphere protects from harmful space weather, such as the solar wind. In the absence of this layer, the solar wind would destroy our atmosphere, resulting in no oxygen left for life on our planet.

    • Harmful Radiation: Earth's magnetosphere coronal mass ejection Protects from the effects of particle radiation and cosmic rays (atoms coming to Earth from distant space) emitted during Coronal Mass Ejection (CME) events.
    • Van-allen Belts: The magnetosphere repels harmful energy away from the Earth and channels it into areas called the 'Van Allen' radiation belts. The amount of radiation may increase as the Sun's activity increases.
      • It is a region of charged particles that is present around the 'magnetosphere' of a planet.
      • There are two such regions on Earth and sometimes other regions have also been created temporarily.

magnetic fields on other planets

  • Magnetic fields on planets: Jupiter, Saturn, Uranus and Neptune All planets have a magnetic field stronger than Earth's, but the underlying process responsible for its creation has not been discovered.
  • planets with no magnetic field
    • Mars: There is not enough temperature in the interior of this planet and at the same time it does not contain the necessary fluid to generate a magnetic field.
    • Venus: It has the presence of a liquid core, but its rotation speed is not sufficient to generate a magnetic field.

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